Francis Perrin's and Frédéric Joliot-Curie's careers from 1910s through 1960s, with particular attention to the state of French science during World War I and after, and to French Atomic Energy Commission (CEA), 1946-1952. This interview was held to discuss a draft of the first four chapters of Weart's book Scientists in Power. Part of the interview consists of Perrin's corrections and comments on various points in the draft, and part covers additional questions raised by Weart.